Monday 18th May comments: Over the last twenty years island residents have been recording all the different moth species that appear on the Isle of May. This is done through ‘moth trapping’ during the night when moths are drawn to a light that is set up over a catching box and then fall down into the box and seek shelter in egg boxes for the remainder of the night. In the morning an eager moth-er (person with a slight interest in moths) counts and identifies all the moths that have been caught, simple! Well, not so simple on some days as many moths can be brown and dull especially if they are coming to the end of their life and their markings are worn. It can take some time scanning through books, taking note of every little detail and occasionally even after all that, some cannot be identified.
In recent years trapping has become more frequent and the number of different species has increased. In 2018, 114 different species of ‘macro’ moths were recorded, the highest total in any one year. Every year new species are recorded for the island and it is through diligent recording that we can use these records to look at national trends and look into the reasons behind the changes.
All the data is collected for the island and sent to the county recorder who collates and checks through the records before putting them into a central database. This can then be used to assess the status of moths in the UK.
By assessing which species are increasing or declining, we can start to look at the reasons why, using moths as biological indicators for the health of our habitats. This includes the potential to assess climate change as we start to see species from the south becoming more common in areas they were not previously found. Including records from the early 1900’s, 250 different species have been recorded on the Isle of May; not bad for one small island in the North Sea.